Feeding mechanism for sewing machines



A. J. WOHLPART.

FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 21, 1918.

v Patented. Mar. 28, 1922.

7 SHEETS-SHEET 1- mmam amuemto'z X- WM I GU01 n2 n3 A. J. WOHLPART.

FEEDING MECHANISM FOR SEWING MACHINES.

PatentedMar. 28, 1922.

7 SHEETSSHEET 2.

APPLICATION FILED MAR-21,1918.

A. J. WOHLPART. FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAIL-21, I918.

l A 1 Q, 6@ v Patented Mar. 28, 1922;

7 SHEETSSHEET 3.

Snow 11 01 A. J. WOHLPART.

FEEDING-MECHANISM FOR SEWING MACHINES. APPLICATION FILED MAR. 21. 1918.

1 A1 ,8'6 Patented Mar. 28,- 19221 1 SHEETS'SHEET 4.

avwemtoz A. J. WOHLPART.

FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 21,1918

Patented Mar. 28, 1922.

7SHEETSSHEET 5.

mmam

WHM also M ed A. J. WOHLPART.

FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 21. 1918.

1,41 0,869,, Patented Mar. 28, 11922,

7 SHEETS-SHEETE.

9: 25' l 2,2 22 f A 9'1 awuaulioz 4 A.-J. WOHLPART.

FEEDING MECHANISM FOR SEWING MACHINES.

APPLICAHON FILED MAR.21,1918.

lfilfifififl, v Patented. Mar. 28, 19212.

AUGUST J. WOHLPART,

COMPANY, OF

OF NEW YORK, N. Y.. ASSIGNOR TO UNION SPECIAL IVIACHINE CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

FEEDING MECHANISM FOR SEWING MACHINES.

1 a citizen of the United States, residing at oil New York, in the county of Bronx, State of New York, have invented certain new and useful Improvements in Feeding Mechanisms for Sewing Machines, of which the follow- I ing is a description, reference being had to the accomfpanying drawing and to the figures of re erence marked thereon.

The invention relates to feeding mechanisms for sewing machines and more particularl to a top feeding mechanism having a feed og engaging the upper surface of the fabric being stitched.

An object of the invention is to provide a top feeding mechanism for a side wheel cylinder machine provided with devices for operating the top feeding mechanism from 'the cross shaft extending through the standard.

A further object of the invention is to provide a machine of the above character with means to adjust the travel of the upper feed dog.

A still further object of the invention is to provide a top feeding mechanism which includes a supporting bracket in which a vertically disposed feed bar carrying the upper feed dog has up and down and back and forth movements, said bracket having guiding devices for guiding the feed bar, which guiding devices may be adjusted relative to each other to take up wear between the parts.

A still further object of the invention is to provide a top feeding mechanism of the above character having a supporting bracket which is attached to the presser bar, with means for taking up the side thrust caused when the top feed bar is on its down stroke and the presser foot is lifted against the tension of the spring which holds the presser foot on the fabric.

These and other objects will in part be obvious and will in part be hereinafter mere fully disclosed.

In the drawings which show by way of illustration one embodiment of my invention;

Fig. 1 is a side view of a sewing machine having my improvements applied thereto;

Fig. 2 is an enlarged sectlon of a portion Specification of Letters Patent. Pwtgntedl Maj-p, 28, 192-2, Application filed March 21, 1918.. Serial No. 223,809.

of the machine from that shown in Fig. l; v

Fig. 3 is an end elevation of the parts at the end of the head of the sewing machine, also showing the end of the cylindrical work support;

Fig. 4 is an enlarged side elevation of the end of the machine viewed from the same position as Fig. 1;

Fig. 5 is a view partly in elevation and partly in section, taken through the rear of the machine;

Fig. 6 is a View partly in, plan and partly in section on the line 66 of Fig. 3;

Fig. 7 is a sectional view on the line 7-7 of Fig. 3, the needles being omitted;

Fig. 8 is a view partly in front elevation and partly in section, showing the. top feeding mechanism, the work support, the looper and the under feed dog with the top feed dog raised from the material and the lower feed dog lowered from engagement with the material;

Fig, 9 is a similar view, but showing the feed dogs engaging the material for feedingthe same, the presser foot being raised;

,Fig. 10 is a sectional view on the line ]01() of Fig. 8 with the needle bar omitted and the clamping arms on the bracket which engage and support the presser bar carrying the presser foot, broken away to show the clamping screw;

F 11 is a perspective view of the upper feed dog; and p Fig. 12 is a section on the line 12 12 of Fig.

l have shown my invention as applied to a side wheel cylinder machine, which includes the opposite side from a supporting base 1, having a standard 2,

carrying anoverhanging arm 3. Projecting from the standard 2 is the cylindrical work support 4:. Mounted to reciprocate in the overhanging arm 3 is a needle bar 5 which is provided with two needles 6- and 7. This needle bar is reciprocated by a needle lever 8, which is connected by a link 9 to the needle bar. The lever 8 at its rear end is connected to an eccentric strap 10 cooperating with an eccentric on the main shaft 11. The main shaft .11 is driven by a suitable belt wheel 12 and a belt guard 13 is provided for protecting the operator from oil.

I spectively, within the work support, are

loopers 18 and 19. The stitch forming mechanism may however be of any Suitable character and forms no part of the present invention.

The material is held on the work support by a presser foot 20. This presser foot-has two spaced forwardly projecting members, each of which is formed with a needle slot 21. Between the two spaced sections of the presser foot is an upper feed dog 22, which engages the upper face of the material for feeding the same to and from the stitching mechanism. Located within the work support is a lower feed dog 23. This lower feed dog is given the usual four motions for assisting in feeding the material to and from the stitch forming mechanism. The feed dogs are arranged and operated so as to feed the material onto the work support. This however, may be varied ifdesired. The lower feed dog 23 may be operated by any suitable mechanism such as shown for example in the patent to Muther et.. a1, #583,415. granted May 25, 1897.

The material is directed onto the work support in one use of the invention, by a feller indicated at 24 in the drawings. This feller is so constructed as to fold the edges of the fabric sections which are to be united and present the same in overlapped relation to the needles. In Figs. 8 and 9, I have shown the fabric sections being joined at F and F.

The present inventionis directed particularly to the mechanism for supporting and operating the upper feed dog 22 and for alternately raising the presser foot. The upper feed dog 22 is carried by a feed bar 25. Said feed dog is clamped to the bar by a clamping, screw 26 which passes through a slot 27 in the shank of the feed dog and is threaded into the lower end of the feed dog supporting the bar 25. The presser foot 20 is carried by a bar 28. This bar 28 is mounted to reciprocate in spaced lugs 29 and 30 carried by the overhanging arm 3. The bar terminates just above the lug 29. The main presser bar for supporting and controlling the presser foot is indicated at 31. This bar 31 is mounted in the lug 29 and in a lug 32 at the upperside of the overhanging arm 3. The bars 28 and 31 are connected by a bracket 33. which also serves as a support for the lever for raising and lowering the upper feed dog and as a guide for the feed bar carrying the upper feed dog. The bracket 33 has spaced arms 34 and 35 which may be drawn together by a bolt 36. The presser bar 28 extends between these arms and is clamped by the arms through the aid of this bolt 36. The bracket is also formed with a split section indicated at 37 and clamping screws 38 and 39 (see Figs. 1 and 6) serve to draw the members of the split section together, so as to clamp the bracket firmly on the presser bar 31.

This split bracket is provided with spaced sections 40 and 41, between which a flat sec tion in the feed dog supporting the bar 25 is adapted to fit and slide. The feed bar 25 moves up and down between these sections and also back and forth laterally. The lower right hand section is in the form of an adjustable gib '42, which is secured by bolts 43 to the upper portion of the section 41. This gib is formed with transverse slots so that the gib may be adjusted toward and from the section 40, so that the width of the slot or recess in which the feed bar slides may be varied so as to take up wear and always maintain a proper support for the feed bar and hold the same against lateral movement in, a direction at right angles to the line of feed. The feed bar is moved back and forth for giving feeding movements to the feed dog through a ball stud connection 44. This ball stud is threaded into the feed bar and the section 40 is formed with a rectangular opening 45,

49, which is mounted in a journal bearing ,carried in a bracket 50, clamped to the rear face of the head at the forward end of the overhanging arm 3. The segment is oscillated by a link 51, which is connected to a ball stud 52, mounted on the segment 48. The link 51 at its rear end engages a bell crank lever 53, which is pivotally supported on a fixed stud 54. The other end of the bell crank lever 53 is connected'to an eccentric strap 55. which cooperates with an eccentric on the main shaft 11. By loosening the nut 56 on the outer end of the T-headed bolt 47, said bolt may be adjusted in the slot 57 formed in the segment and'thus the throw of the link 46 may be varied and as the throw of this link is varied. the lateral movement of the feed bar 25 will be varied and this will vary the feeding stroke of the upper feed dog. The curved slot 57 is concentric to the center of the stud 44 when the feed dog is at the extreme rear end of its stroke. Therefore, when the stroke of the upper feed dog is increased, said feed dog will move farther forward but will stop at the same point in its rearward travel. The feed bar 25 is moved up and down through a connection with a rock shaft 58. This rock shaft is fulcrumed in a sleeve 59 formed integral with the bracket 33 (see Figs. 8, ,9 and 10). Mounted on the rock shaft and projecting forwardly therefrom, is an arm 60. Said arm is forked at its forward end. Located between the forked sections of the'arm 60 is a sleeve 61. A hollow journal pin 62 extends through this sleeve and forms a pivotal connection between the sleeve and the forked arm 60. The sleeve has a central opening through which the upper end section 63 of the feed bar extends. The hollow journal pin has an opening extending therethrough', through which this section 63 of the feed bar extends, which serves to hold said hollow journal pin in place. This opening is sufliciently large, so

that the feed bar may move freely up and down in the sleeve and hollow journal pin. Said sleeve has a reduced section between its upper and lower ends which receives the forked sections of the arm 60. A spring 64 surroundsthe feed bar and bears at its upper end against the lower end of the sleeve 61. The lower end of said spring 64 bears against a shoulder 65 on the feed bar 25. The upper end of the feed bar is threaded to receive two nuts 66 and 67.

The rock shaft 58 at its outer end carries an arm 68, which is clamped to the shaft 58 by screws 69. A ball stud 70 is mounted on the lower end of the arm 68. A link 71 engages this ball stud at its forward end and the rear end of this link is connected with a ball stud 72 adjustably mounted in a slot 73 formed in the depending arm of a rock lever 74. The other arm of. the rock, lever carries a ball stud 75, which is engaged by an eccentric strap 76 and the eccentric strap 76 cooperates with an eccentric on the main shaft 11. This rock lever 74 is mounted on the fixed stud 54. As the main shaft rotates, thelink 71 will be moved endwise and this will oscillate the shaft 58 and through the arm 60 raise and lower the feed bar carrying the upper feed dog. The amount of lift or the extent to which the feed bar is raised, can be varied by adjusting the ball stud 72 in the slot 73. When the feed dog is at its extreme low point of'travel, the slot 73 is concentric with the ball stud 70 and therefore when the stud 72 is adjusted inthe, slot 7 3, the feed dog will be raised a greater distance above this extreme low point of travel, which will be uniform for all adjustments.

When the shaft 58 is oscillated so as to raise the outer end of the arm 60, the sleeve 61 engages the nut 66 and raises the feed bar. When the shaft 58 is moved in the opposite direction, the spring 64 will maintain the nut 66 against the upper end of the sleeve 61 and these parts will move down together until the feed dog engages the material. The downward movement of the feed dog will then cease but the end of the arm 60 will continue its downward movement compressing the spring 64 until the coils of the spring are brought together. Further downward movement of the end of the arm 60 will then cease and the feed bar will then become an abutment or a fulcrum, so that as the shaft 58 continues to oscillate in the same direction, the sleeve 59 and the bracket 33 of which it is formed a part, will be raised and as this bracket is clamped to the presser bars, the presser foot will be raised. It is to be noted that the feed dog will engage the fabric for a brief time before the presser foot is raised; that is, while the spring 64 is being collapsed and therefore, I am able to maintain constant control of the material. When the shaft 58 is moved in the opposite direction, the presser foot .Will be lowered onto the material and the outer end of the arm 60 will be raised and come into contact with the nut 66 and then raise the feed bar so that the presser foot will engage the material for an interval of time before the upper feed dog is raised. This spring and the lost motion in the connection betweenthe shaft 58 and the upper feed bar, not only permits continuous control of the feedof the-material and the holding of the same on the work support, but it also obviates a reboundin the flat pressure spring 77 controlling the tension or .downward'pressure on the presser foot. The eccentrics operating the upper feed bar are of course timed in unison with the device operating the under feed. The upper and lower feed dogs are prevented from coming into contact by a bracket arm 78 which is adjustably connected to the head of the machine by a screw 79, which passes through a slot 80 in the bracket. I screw 81 is threaded into the feed bar and this bracket extends underneath this stop screw. When there is material in the machine, the extreme low point of travel of the feed dog is such that this stop screw is out of contact with the bracket. When however, the material is removed from the machine, the stop screw will come into contact with thebracket and prevent engagement of the upper feed dog with the lower feed dog. The bracket 33 is held from movement under any side thrust of the feed bar by a right angle gib 82, which is secured to the head of the overhanging, arm by screws 83.

From the above it will be apparent that I have provided an upper feed dog operat-' ing mechanism wherein the feed bar sup- A stop stantly under control.

It is obvious that minor changes in the details of construction may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is':,

1. A sewing machine including in combination, a cylindrical work supporting arm, an overhanging arm, a pressure foot, and

' a feeding mechanism for feeding. the material lengthwise of the work supporting arm, said feeding mechanism including a vertically arranged feed bar carried by the overhanging arm, an upper feed dog rigidly carried by said feed bar, means connected at the upper end of the feed bar for raising and lowering the same,'said means providing a fulcrum about which the feed bar may swing for its feeding movements, means engaging the feed bar between its ends for guiding the feeding movements of the feed bar in a plane parallel with the longitudinal axis of the work supporting arm, a rock lever carried by the overhanging arm, a

" link connecting said rock lever with the feed bar for imparting feed movements to the feed dog, and means for oscillating said rock lever.

2. A feeding mechanism for sewing machines including in combination a work support, a presser foot, an upper feed dog engaging the material on the work support, a'vertically arranged feed bar to which said "feed dog is rigidly connected, means connected to the-upper end of thfeed bar for raising and lowering said feed bar for each vfeeding movement, said means providing a fulcrum about which said feed bar may swing for its feeding m'ovements, means engaging the feed bar between its ends for guiding the swinging movements of the feed bar, means for swinging said feed bar for imparting feed movements to the feed dog, said means for raising and loweringthe feed bar including a spring whereby the feed dog is yieldinglypressed against the material.

3. A feeding mechanism for sewing machines including in combination a work support, a presser foot, anupper feed dog engaging the mater al onthe work support, a vertically arranged feed bar carrying said upper feed dog, means for guiding said feed bar 1n its movements, means for moving the feed bar back and forth for imparting feed movements to the feed dog, and means for alternately raising said feed bar and presser" foot, said means including a lever having a free' sliding connection with the feed bar, means for positively limiting the movement of the lever lengthwise of the feed bar in a direction away from the material, and a spring for limiting the movement of the lever along the feed bar in a direction toward the material, whereby said feed dog is yieldingly pressed into contact with the material and positively lifted from engagement therewith. I

4. A feeding mechanism for sewing machines including in combination a work support, a presser foot, an upper feed dog engaging the material on the work support, a vertically arranged feed bar on which the upper feed dog is fixed, a bar supporting the presser foot, a bracket connected to the bar supporting the presser foot, said bracket having spaced v arms forming a guiding slot for the upper feed bar, means for raising and lowering the feed bar and means for moving the feed bar back and forth in the slotfor imparting feeding movements to the feed dog, one of said arms forming a guiding "slot having an adjustable gib against which the 'side of the feed bar bears.

5. A feeding mechanism for sewing machines including in combination a work support, a presser foot, an upper feed dog engaging the material on the work support, a vertically arranged feed bar on which the upper feed dog is fixed, a bar supporting the presser foot, a bracket connected to the bar supporting the presser foot, said bracket having spaced arms forming a guiding slot for the upper feed bar, a shaft fulcrumed on said bracket and having an arm connected to the upper, end of the. feed bar, means for oscillating said shaft for alternately lifting the feed dog and presser foot.

6. A feeding mechanism for sewing machines including in combination a work support, a presser foot, an upper feed dog engaing the material on the work support, a

vertically arranged feed bar carrying the up er feed dog, a bar supporting the presser foo a. bracket connected to the bar supporting the presser foot, said bracket having spaced arms-forming a guiding slot for the upper feed bar, a shaft fulcrumed. on said bracket and having an arm connected to the upper end of the feed bar, means for oscillating said shaft for alternately lifting the feed dog and resser foot, and a bearing. gib for guiding he bracket in its vertical movements and for taking up the side thrust on the bracket.

7. A feeding mechanism for sewing mameans connected to the feed bar vertically arranged feed bar carrying the upper feed dog, a bar supporting the presser foot,a bracket connected to the bar supporting the presser foot, said bracket having spaced arms forming a guiding slot for the upper feed bar, a shaft journalled in said bracket, said shaft having a. forwardly projecting forked arm, a sleeve journalled in said forked arm and having a sliding connection with the upper end of the feed bar, devices at the upper end of the feed bar against which saidsleeve bears, a coil spring encircling the feed bar and bearing against said sleeve at its lower end, said feed bar having a shoulder engaged by the lower end of said spring, said spring being so proportioned that as the lever oscillates, the coils of the spring will engage each other, so that the spring may serve as an abutment for the lifting of the presser foot and means for oscillating said lever.

8. A feeding mechanism for sewing machines including in combination a work support, a presser foot, an upper feed dog engaging the material on the work support, a vertically arranged feed bar carrying the upper feed dog, a bar supporting the presser foot, a bracket connected to the bar supporting the presser foot, said bracket having spaced arms forming a guiding slot for the upper feed bar, one of the arms of said bracket having an opening formed therein, a ball stud secured to the feed bar and extending outwardly through said opening, a

link connected to said ball stud, a segment lever journalled on the arm of the machine and having a slot for a T bolt with which the other end of said link is connected and means for oscillating said segment lever.

9. A sewing machine including in combination a standard, a cross shaft extending through said standard, an overhanging arm projecting at right angles to the cross'shaft, a cylindrical work support beneath said arm, a presser foot for holding thematerial on the work support, an upper feed dog, a vertically disposed feed bar carrying the upper feed dog, a bracket having a guiding bearing for the feed bar, a lever mounted on the bragket for alternately raising the feed bar and the presser foot, a link connected to said lever, a rock lever on the overhanging arm to which the other end of said lever is connected, an eccentric on the main shaft and an eccentric strap cooperating therewith for oscillating said rock lever and the feed bar back and forth for imparting feeding movements to the feed dog.

10. A sewing machine including in combination a standard, a cross shaft, an overhanging arm extending at right angles to for moving.

the cross shaft, a cylindrical work support beneath said overhanging arm, a presser foot for holding the material on the work support, an upper feed dog, a vertically arranged feed bar supporting the feed dog,

.a bracket having a guiding bearing for the feed bar, a link connected to the feed bar for moving the feed dog back and forth, a segment lever to which said link is adjustably connected, a second link connected to said segment lever and to the rock lever directly over the cross shaft, an eccentric on the cross shaft and an eccentric strap cooperating therewith and connected to said rock lever and means for raising and lowering the feed bar.

11. The combination with a standard, a work supporting arm projecting from the standard, an overhanging arm carried by the standard, a main shaft extending through the standard in a direction at right angles to a plane containing the overhanging arm andthe work supporting arm, apresser foot, an upper feed dog for engaging the material on the work support and for moving the material in a direction longitudinally of the work support, a feed bar carrying said upper feed dog, means for guiding said feed bar in its movement, i'neans operated by the main shaft for moving the feed bar back and forth for imparting feeding movements to said dog and means operated by the main shaft for raising and lowering the feed bar.

12. The combination with a standard, a work supporting arm projecting from the standard, an overhanging arm carried by' the standard, a main shaft extending through the standard in a direction at right angles to a plane containing the overhanging arm and the work supporting arm, a presser foot, an upper feed dog for engaging the material on the work support and for moving the material in a direction longitudinally of the work support, a feed bar carrying said upper feed dog, means for guiding said feed bar in its movement, means operated by the main shaft for moving the feed bar back and forth for imparting feeding movementsto said dog and means operated by the main shaft for raising and lowering the feed bar, said means for raising and lowering the feed bar including devices for raising the presser foot.

13. The combination with a standard, a work supporting arm projecting from the) standard, an overhanging arm carried by the standard, a main shaft extending through the standard in a direction at right angles to a plane containing the overhanging arm and the work supporting arm, a presser foot, an upper feed dog for engaging the material on the work support and for movsaid feed bar in its movement, means opbar including a link operated from said 10 erated by the main shaft for moving'the main shaft, said links being parallel with feed bar back and forth for imparting feedthe work supporting arm.

ing movements to said dog and means op- In testimony whereof, I afiix my signaerated by the main shaft for raising andture in the presence of two witnesses. lowering the feed bar, said means for mov- AUGUST J. WOHLPAR-T. ing the feed bar back and forth including a Vitnesses:

link operated from said main shaft, said V. BLANGHARD,

means for raising and lowering the feed FRANK J. ROTHAUG. 

